Failure of cables, wires, ropes, webbing (referred to herein as cordage) in lifting, supporting, guying, holding, or staying objects is a serious problem. Associated with the problem is the need to provide for operators of cordage equipment an adequate warning of impending failure of cable, wire, etc. when under tension or other potentially dangerous situations. In recent years various electronic devices have been introduced to provide such warning by determining potentially dangerous conditions such as overload due to stress or weight, but these rely on an uninterrupted source of electricity. Scales of various types have also been introduced into the load-cordage sequence to determine overload due to weight, but both of the above methods are invariably fragile, and both of these methods require frequent recalibration, are expensive, and are difficult for operators of equipment to continuously monitor. Also, the previous methods will not indicate other dangerous conditions including transients that may affect tension conditions in cordage.
Some manufacturers of webbing have attempted to resolve this problem by introducing vari-colored threads into the body of the webbing, which, when becoming apparent to the operator, indicate an overload condition. This, however, indicates an irreversible condition of overload, not a warning which allows one to proceed with caution after repair.